Recently, electric compressors in which electric motors are used as power sources have been adopted as compressors used for vehicle air conditioners. As such an electric compressor, an inverter-integrated electric compressor in which an inverter accommodating portion is provided in a housing, and an inverter device that converts DC power from a high-voltage power supply into three-phase AC power and supplies it to the electric motor is accommodated in this inverter accommodating portion has been put to practical use. As disclosed, for example, in Patent Documents 1 and 2, this inverter device has a printed circuit board provided with a power switching device, a smoothing capacitor, and a control circuit that constitute an inverter circuit and also has a connector for connecting to an external DC power supply or a motor unit. Each of these components is wired and connected using a bus bar integrated plate. This bus bar integrated plate is used as a bus bar assembly in which a plurality of bus bars are integrated with resin insert-molding and secured on an outer peripheral surface of the housing wall while maintaining insulation (see Patent Documents 1 and 2).
In addition, as disclosed in Patent Document 3, a bus bar structure is generally constructed such that a plurality of bus bars formed of an electrically conductive metal and an insulating base made of synthetic resin are laminated. A connecting piece projects from this bus bar laminated body in the horizontal direction of the bus bar laminated body to be wired and connected by welding with each bus bar or various electrical components. On the other hand, as disclosed in Patent Document 4, there are also bus bars having a cross-linked shape that are not provided with an insulating base.    Patent Document 1: the Publication of Japanese Patent No. 3827158    Patent Document 2: the Publication of Japanese Patent No. 3760887    Patent Document 3: Japanese Unexamined Patent Application, Publication No. 2002-281643    Patent Document 4: Japanese Unexamined Patent Application, Publication No. 2004-80873